Nematicidal Activity of Fungal and Bacterial Metabolites against Meloidogyne incognita Eggs Infesting Mulberry

Abstract

Mulberry (Morus alba L.) serves as the exclusive host plant for the silkworm (Bombyx mori L.) and is cultivated mainly for its nutritious foliage. However, leaf yield and quality are adversely impacted by several soil-borne pathogens, with root-knot nematode (Meloidogyne incognita) being one of the most destructive pests. The present investigation was conducted in vitro at the Department of Plant Pathology, College of Sericulture, Chintamani, to evaluate the nematicidal efficacy of secondary metabolites extracted from selected biocontrol agents, including Paecilomyces lilacinus, Lecanicillium lecanii and Pseudomonas fluorescens. A total of five treatments were tested, each replicated four times, and both egg hatching inhibition of M. incognita were assessed at four concentrations (25%, 50%, 75%, and 100%) over a 72-hour period under in-vitro conditions. The study revealed that these metabolites effectively suppressed egg hatching when compared to untreated control plates. Notably, Paecilomyces lilacinus exhibited the highest suppression, recording 85.60 per cent egg hatching inhibition after 72 hours of incubation at 100 per cent metabolite concentration. These results suggest that fungal secondary metabolites, particularly from P. lilacinus, offer promise potential as eco-friendly alternatives for managing M. incognita in mulberry cultivation systems.